1. Field of the Invention
The invention relates to a three-phase rotary electric machine, and in particularly, to a three-phase rotary electric machine in which three-phase coils wound around a stator core are resin-molded.
2. Description of Related Art
Conventionally, as this kind of three-phase rotary electric machine, a solution is proposed in which a plurality of through-holes penetrated through the stator core in an axial direction are provided at an outer circumferential side of a coil end of the stator core (e.g., referring to Japanese Patent Application Publication No. 2013-176183 (JP 2013-176183 A)). In this three-phase rotary electric machine, riveting is carried out by inserting rivet pins in the plurality of through-holes, so that the stator core is configured integrally. During injection molding, residual air is discharged to the outside from the through-holes for rivet pins, thus formation of voids formed by the residual air is suppressed.
As for the injection molding, in order to reduce formation of the voids, generally resin is injected from a lower portion side of the stator core. Therefore, in the above three-phase rotary electric machine, when the lower portion of the stator core is filled with resin, the residual air is discharged to the outside via the through-holes for rivet pins. However, when an upper portion of the stator core is filled with resin, the through-holes for rivet pins are closed, so that it is difficult for the residual air to be discharged to the outside, thereby voids are formed. For this problem, it is also considered a solution in which air holes and/or grooves are formed to discharge the residual air to the outside, but in this case, the resin will flow to the outside to form foreign substance.